Not applicable.
Not applicable.
The invention relates to a method of recording a vibration isolation system having at least one vibration isolation device that can be assigned to an isolation element th vibration isolation system being assigned as at least one of a closed-loop or open-loop control device; a computer program for carrying out the method on a computer wherein the computer program comprises a plurality of program modules; an apparatus for carrying out the method and for executing the computer program wherein the at least one of the closed-loop or open-loop control devices comprises at least one of a controller unit or user-oriented function units; and a system for recording a vibration isolation system that comprises an apparatus for carrying out a computer program.
Methods for vibration isolation are known in which the control of a vibration isolation system is carried out on the basis of a substantially fixedly predefined parameter set. In particular, the missing or inadequate possibilities of monitoring or diagnosis, that is to say the absence of fault detection and elimination on the vibration isolation system, have been shown to be a problem in the vibration isolation of existing systems.
Known methods, computer programs and apparatuses for vibration isolation also have the disadvantage that they provide barely any interfaces via which, for example, diagnostic data are or can be picked off in a simple way, processed and made available to the user.
However, the difficulty of gaining access to data hampers not only the monitoring of the vibration isolation system but also flexible adaptation of the same to new or unforeseeable states or situations.
It is therefore an object of the invention to provide an open system for recording and/or assessing a vibration isolation system.
According to the invention, this object is achieved, inter alia, by a method of recording a vibration isolation system having at least one vibration isolation device that can be assigned to an isolation element, the vibration isolation system being assigned at least one of a closed-loop or open-loop control device, including the following steps:
providing at least one of a closed-loop or open-loop control structure;
picking up and processing signals and/or variables related to the isolation system by exciting the vibration isolation system into vibration,
forming at least one isolation system characteristic reference fingerprint data set on the basis of the control structure and the recorded variables for assessing the vibration isolation system,
recording and forming an actual fingerprint data set,
comparing at least part of the reference fingerprint with at least part of the actual fingerprint, and
assessing the state of the vibration isolation system on the basis of specific deviations between the reference and the actual fingerpint.
Furthermore, for the purpose of achieving the object, a system as claimed is specified, which comprises the method, the computer program having the features as claimed and the apparatus having the features as claimed.
In relation to a vibration isolation system, which comprises at least one vibration isolation device that can be assigned to an isolation element, the fact that a method of recording the system with the aid of a closed-loop and/or open-loop control device is provided, in which a closed-loop and/or open-loop control structure can be predefined and in which signals and/or variables related to the isolation system are picked up, processed and/or provided, and in which, on the basis of the definable structures and variables, at least one isolation system characteristic data set for assessing the vibration isolation system is formed, means that for the first time the indicative fundamentals for an open system for evaluation, closed-loop and open-loop control are provided.
In this sense, the method as claimed by the invention offers the possibility of adapting the closed-loop and open-loop control structure provided in a differentiated manner to individual requirements. In this case, provision is advantageously made, in particular within the context of the provision of the closed-loop and/or open-loop control structure in flexible form, for the provision of an extremely wide range of control loops to be made. In this way, the method permits the definition of diverse types of control, such as feedback and/or feed-forward control. In order, moreover, also still to be able to compensate for time fluctuations in the isolation system, the closed-loop and/or open-loop control structure according to the invention also offers the possibility of adaptive control, that is to say the ability of the method to adapt itself to aging processes or external influences, for example.
The variability of the method is also expressed in the fact that in the method, in particular acceleration-determined and/or speed-determined and/or position-determined control loops in the closed-loop and/or open-loop control structure can be selected and defined, in particular independently of one another. Appropriate actuators and control variables or sensors tuned to the isolation system are likewise specified in the method of the invention. For this purpose, the controlled variables in the closed-loop and open-loop control structure can be specified individually, in particular in relation to the actuators and sensors. Examples which may be mentioned here are variables such as in particular limiting values for overload currents with regard to motors belonging to actuators or else controlled variables relating to a pneumatic vibration isolation system.
Also connected with this is the fact that, according to the invention, the possibility is advantageously open of tuning the control loops per se and amongst one another in an extremely differentiated manner. Stabilization or self-stabilization of the vibration isolation system is therefore achieved, with very positive effects. In this case, for example, changeover criteria between the control loops can be defined or individual filters and/or amplifiers can be adjusted, for example with reference to controller gain factors. In addition, mention should be made in particular of the possibility that, with regard to each axis to be isolated, the scope of the influence which the respective signals picked up or sensor signals have or are to have on the axis to be isolated can be determined or predefined. The same is also true of the output signals for the control of the actuating variables.
In addition to the parts of the method already specified above, the method of course also includes the closed-loop and/or open-loop control of the vibration isolation system, in particular on the basis of the control structure provided and/or with the aid of the variables and/or signals and/or of the isolation system characteristic data set. The closed-loop control and/or open-loop control and the control structure provided in this case relate in particular and primarily to all the inventive aspects known and still to be explained relating to vibration isolation and preferably to all the degrees of freedom which are available or are to be isolated.
Consequently, a significant aspect of the invention also consists in particular in providing interfaces of an extremely wide range of types, in order to permit substantially optimal data processing. What are preferably concerned here are interfaces to the hardware and those to the software on the basis of program code means and/or the adaptation of software to existing hardware interfaces, and user interfaces. In this case, the interfaces are used firstly for the acquisition and for the interchange of signals and data between the vibration isolation system and the closed-loop and/or open-loop control device or else, in addition, for the internal forwarding or further processing in the closed-loop and/or open-loop control device and for man-machine data interchange. Furthermore, however, according to the invention provision is also made to provide interfaces which permit the feeding of external signals, for example excitation signals for the vibration isolation system, and those which permit signals to be picked off in a specific way. In the case of the latter, they may be, for example, actuating variables/actuating signals or control deviations in a control loop. Use is preferably made of serial interfaces, for example interfaces which are based on the RS232 standard, as internal interfaces in the closed-loop and/or open-loop control device.
However, the method according to the invention includes not only the provision of interfaces but also their monitoring and/or control and/or configuration with regard to data interchange. In this case, for example, it is also ensured that a parallel interface can be used not only by an application in the closed-loop and/or open-loop control unit, but that the interface can be used by a plurality of applications at the same time. Furthermore, parallel operation with a plurality of interfaces is also ensured. In addition, interfaces can also be coordinated in such a way that remote control of the vibration isolation system is possible. According to the invention, the latter can be made possible, for example, by providing DCOM functionality (Distributed Component Object Model functionality).
In order to secure the configuration data provided for the closed-loop and/or open-loop control structure, the data or signals picked up and the data sets formed, their recording or storage or saving is advantageously provided within the context of the method. In this way, the information is also retained for subsequent applications, for example for comparison and/or for export.
In a further advantageous development of the method according to the invention, the latter likewise also includes the testing of the closed-loop and/or open-loop control structure. In this case, in the method, for example, external excitation signals are provided or fed in via the interfaces provided and/or processing steps for the test excitation of the vibration isolation system or, for the same purpose, internal excitation signals are generated. The result of the test excitation is recorded in the closed-loop and/or open-loop control device, is further processed and recorded. In accordance with the invention, the test excitations can advantageously be configured in detail and stored. To this end, examples which may be mentioned are the specification of the excitation on specific degrees of freedom or on specific control loops.
A further substantial and advantageous aspect of the invention also consists in the fact that flexible monitoring functions are provided which, for example in the context of defining or configuring monitoring or tolerance criteria, can be used for general or permanent testing of method steps and/or parameters or variables, for example in the form of background monitoring. To this extent, provision is made within the context of the invention, for example, to monitor the functioning of actuators. In specific terms, for example temperatures and states of actuating motors and the control of a pneumatic vibration isolation device and the actuating offset of the valves used there can be monitored. Furthermore, the monitoring function of the invention is advantageously designed in such a way that in principle all closed-loop and open-loop control variables, for example control loop tuning variables, are accessible for background monitoring. However, the invention is not restricted to the higher-order general or permanent testing of all the relevant vibration isolation variables; instead monitoring areas can be selected in a differentiated manner, so that for example the monitoring possibilities can also be referred to selectable control loops and, in the latter, for example, to individual degrees of freedom to be monitored and, in this case, in turn to associated actuating variables. Within the context of the invention, nothing stands in the way of further differentiation of the monitoring. Here, it should also be pointed out that the selection of the monitoring data exists not only in relation to the quasi-vertical directionxe2x80x94on this point, see the preceding explanationsxe2x80x94but also in the horizontal direction, that is to say it is also possible for monitoring data from an extremely wide range of regions to be associated with one another.
In a particularly advantageous development of the method according to the invention, provision is made therein to form a specific fingerprint for the vibration isolation system, by using which, for example, comprehensive characterization and/or assessment of the isolation system can be performed. The terminology of the fingerprint to this extent designates in particular an identification pattern for a vibration isolation system based on a predefined closed-loop and/or open-loop control structure. In addition to characteristic data sets, the fingerprint also contains information about functional relationships which are specific to vibration isolation and using which an isolation system can be described.
In this case, for example, power spectra of vibrations are picked up and/or determined. What are concerned here are, firstly, in particular vibrations that excite the vibration isolation system and, secondly, in particular vibrations which originate from the isolation element and which represent the reaction of the isolation element to the excitation. In addition, the fingerprint advantageously contains in particular information relating to transfer functions, from which in particular the resonant behavior of the isolation element may be read off with reference to the exciting vibration. Corresponding pointers can be determined, for example, from the vibration phase function, that is to say the phase profile with regard to exciting and resulting vibration. Therefore, appropriate data can be and is likewise assigned to the fingerprint. Important conclusions relating to the vibration behavior and/or the change behavior of the vibration isolation system or the vibration isolation device or the isolation element, in addition to the functional relationships already mentioned, can in particular also be obtained from the coherence of the vibrations, so that, according to the inventions, the characteristic fingerprint also comprises such information or data sets.
It should be pointed out that the abovementioned variables, which are picked up and/or determined in accordance with the invention, within the context of the invention are of course not just essential data for the fingerprint to be formed, but to this extent also concern important data in that on their basis, in the method according to the invention, inter alia control deviations can be determined with the aid of which actuating signals or actuating variables can be calculated, which can be fed back to the actuators. A fingerprint in the sense of the invention therefore in particular also constitutes a substantial part of the control structure since, as outlined above, in particular the time behavior of the vibration isolation system and therefore also changes under defined conditions can be read off and/or defined from it.
A further most advantageous development of the method consists in the possibility of determining the fingerprint according to the invention on the basis of simulation as well. This may be a pure simulation, within the context of which the vibration isolation system is simulated completely with the aid of a computer. However, the simulation can also consist in the vibration isolation system being simulated as a model on a laboratory scale, in order in this way to obtain a fingerprint in advance. Mixed forms of the simulation are of course also conceivable and provided.
Of course, the method advantageously also includes the recording or storage and the possibility of the import and export of correspondingly previously held or recorded fingerprints or at least part thereof. According to the invention, not only is pure static recording provided but, at the same time, dynamic recording is possible. In the sense of the invention, to this extent dynamic is to be understood in particular to mean continuous or multiple recording of fingerprints within specific time limits and intervals.
Within the context of the invention, for example vibration tolerance bands can be defined in an extremely advantageous manner via a comparison of at least two fingerprints or at least parts of the same. Furthermore, a fault register or a fault database can be built up in this way for the vibration isolation system, an assignment of faults in the vibration isolation system, which are expressed by a one or more specific deviations in the fingerprint as compared with a reference fingerprint, being carried out in the fore-ground by means of a comparison of fingerprints. Diagnostic capabilities are therefore most advantageously also associated with the method according to the invention. This means that, with the fingerprint according to the invention, faults or deficiencies can not only be determined and checked but also classified, in order in this way to be able to classify states of the vibration isolation system. A distinction is drawn to this extent, for example, between faulty states or deviations from the original state of the vibration isolation system which are caused by the vibration isolation device, and those which originate from the isolation element. Furthermore, however, it is also possible in detail for changes on the isolation element or in the vibration isolation device which have an effect on the vibration system to be self-triggered and detected. For example, in this connection mention should be made of the loosening of a hose or that of a screw on the isolation element. In this case, for example the fingerprint diagnosis can notify the user which hose has been loosened and at which point the hose is located, for example in relation to the isolation device. Such information is very useful to the user, since in this way repair times and therefore also production idle times can be reduced considerably.
It is not only the diagnostic capability of the method but also a method or system that is capable of learning which is founded in connection with the specification according to the invention of state fingerprints. The ability of the system to learn relates in particular to the continuous expandability of the fault database according to the invention, it being possible for the expansion according to the invention to be carried out, for example, via import interfaces or user interfaces. Furthermore, however, self-teaching is also provided in accordance with the method of the invention. For this purpose, for example, the diagnostic function and/or the control loops of the invention are preferably further supplemented by fuzzy logic or by fuzzy controllers, on the basis of which even only an inaccurately known relationship between disturbance and controlled variables and/or even the inaccurate relationship between two fingerprints can be quantified and determined.
A further advantageous development of the subject of the invention is also to be seen in the fact that the method in principle includes visualization of all the variables and/or data and/or relationships. This means, inter alia, that the behavior of the vibration isolation system or of the isolation element according to the invention can be displayed, in particular in three-dimensional form, within the context of all the tests, simulations and during active operation, on the basis of a user-oriented interface.
In addition to the method according to the invention, presented above, the invention also relates to a computer program for carrying out the method of the invention when the program is executed on a computer. In this case, the computer program according to the invention is distinguished by individual program modules which comprise object-specific, function-specific and user-specific computer program parts as a unit. Here, overlaps, for example in relation to diagnostic and test-specific program parts, are possible and provided. In a first specification, substantially two program parts can be distinguished according to the invention. These are, firstly, the controller-related software and the PC or host-system related software.
The core for vibration isolation is in this case the controller software, which is substantially responsible for the vibration isolation of the vibration isolation system. It also activates the appropriate interfaces to the vibration isolation device, that is to say to the device which in particular can comprise the isolation table, the sensors and actuators and possible further actuators, in particular also a pneumatic vibration system, and to the host system.
Furthermore, however, the controller module also has diagnostic capabilities relating to the vibration isolation system, in that for example overload currents of actuating motors are monitored independently and system instabilities can be controlled out automatically. In addition, the controller software possesses, inter alia, the capability of carrying out diagnostic tests of the vibration isolation system, suitable interfaces being provided for this purpose which, for example, also permit test excitation of the isolation system from outside.
For the communication with the host system, the controller module provides, for example, a command-driven RCI (Remote Command Interface) via which, inter alia, all the parameters of variables registered by the controller can be transmitted in digitized form to the PC/host system.
PC-based or host-system-based program parts of the computer program according to the invention substantially comprise user-related function modules, in particular for communication with and/or control of the controller module and/or of the controller. In their function as, in particular, user interfaces to the vibration isolation system, they expand in particular the diagnostic capabilities of the overall system comprising vibration isolation system and/or closed-loop and/or open-loop control device. In this case, function modules or program tools for installation and/or visualization and/or diagnosis and/or control loop tuning and/or controller function monitoring can be distinguished, overlaps in the function also being provided here and, if expedient, also being implemented.
Furthermore, in order to carry out the method according to the invention and to execute the computer program according to the invention, the invention also specifies an apparatus which comprises one or more components arranged for vibration-isolating operation, in particular sensors and/or actuators, which cooperate with a closed-loop and/or open-loop control device in such a way that at least one data set that is characteristic of the vibration isolating system can be provided. The closed-loop and/or open-loop control device is preferably likewise of modular design, corresponding to the computer program modules.
The same also applies to the system claimed by the invention for recording a vibration isolation system.